A sensor device can be placed on the upper-body of a user (e.g. chest area) to sense an analog, single-lead, bipolar electrocardiogram (ECG) signal through electrodes that are attached to the skin of the user. The analog ECG signal is sampled and converted to the digital domain using an analog-to-digital converter (ADC) and is passed to a signal processing unit of the sensor device to extract R wave to R wave intervals (RR intervals) and other related features of the ECG signal.
Typically, several ambient noises such as motion artifacts and baseline wander, caused by the movement of the user, are mixed with the ECG signal and thus picked up by the sensor device resulting in less accurate ECG signal detection. Conventional methods of filtering detected ECG signals include filtering the ECG signal using a fixed analog anti-aliasing filter before the ECG signal is converted to the digital domain by an ADC and then filtering the ECG signal using a digital band-pass filter that removes the baseline wander and the out of the band noise.
However, these conventional methods do not adequately filter ECG signals with changing parameters. Therefore, there is a strong need for a cost-effective solution that overcomes the above issue. The present invention addresses such a need.